Events you meant to mention
Most of what you noticed this week has already passed.
People tend to have small groups they go to things with. A few friends who are into art and go to exhibitions together. The group that meets up for talks after work.
The pattern is always the same. You see a talk you'd both like, mean to bring it up next time you're in touch, and by then it's gone. Not because it wasn't worth sharing, just because there was too much of it to send each one as a message.
A list you can all see changes this. You each add what you've noticed, and any of you can look when you want to. Some things get picked up and turn into evenings out. Most things don't, and that's fine - they were options, not invitations.